January 12, 2026
Solar Panel Curtailment in Belgium: How Can You Protect Your GSC Revenue When Prices Are Negative?
Published by
Willian van de Sande
Covolt Netherlands
Starting April 1, 2026, curtailment of solar panels in Belgium will no longer be a choice—it will become a financial necessity. The Flemish government has approved an amendment to the Energy Decree under which Green Power Certificates (GPCs) will no longer be awarded during hours with negative day-ahead prices. Anyone who continues to feed electricity into the grid unchecked will not only lose GPC revenue but will also have to pay for the electricity they feed back into the grid. Covolt automatically curtails your solar panels during periods of negative prices—so you don’t lose a single euro due to a measure that was bound to happen anyway.
Want to learn more about how to prevent curtailment or how Fall-Back Flex works as a Belgian flexibility service?
Why this measure? Preventing grid congestion during injection
Just like in the Netherlands, Belgium is also increasingly facing grid congestion. This problem arises not only when demand is high, but also when excessive injection of electricity at times of high solar production.
Large-scale PV installations can lead to structural overproduction, which puts pressure on the electricity grid. With the elimination of GSCs at negative prices, it becomes less financially attractive to inject electricity into the grid in an uncontrolled manner.
Who will be affected by this new decision?
- All production technologies: Wind, CHP, biomass, and solar panels
- Exceptions:
- <400 kW bruto nominaal vermogen (bestaande installaties)
- <200 kW voor installaties die vanaf 1 januari 2026 in gebruik worden genomen.
Capturing excess power with a battery? That’s also an option! But not everyone has the authorization or funding to invest in a battery. Also, battery management can be handled by Covolt provide support.
What is the financial impact of this decision?
In the past, GSCs made injection profitable even at negative prices. That advantage is now disappearing completely.
Some figures:
- In 2025, more than 500 negative hourly prices were recorded on the day-ahead market. That accounts for +6% of all hours in 2025!
- An average PV system of 700 kWp can save between €5/kWp and €20/kWp at negative hourly prices.
- The Flemish Government calculated that by not providing support for production during periods with a negative price of 1 hour, 40% fewer GSCs would be awarded during that same period.
In short: Flexible management pays off!
Smart curtailment with 2 setpoints as a solution
At Covolt Belgium, we work with setpoints to intelligently control PV systems. Depending on current consumption needs and market prices, the inverters’ output is automatically adjusted. In doing so:
- No injection at negative day-ahead prices
- Maximum use of directly consumed solar energy
- Avoiding negative price impact
Important: Also for self-consumed electricity during negative prices no GSC are not granted. This measure therefore has a double impact!
How do those two setpoints work?
At Setpoint 1 – Negative price threshold: As soon as a negative price point is detected, production is reduced to the level of own consumption. The power of the inverter is increased or decreased depending on current consumption.
At Setpoint 2 – Complete shutdown: When the price level becomes so low that your own consumption is more expensive than purchasing electricity from the grid, the PV system shuts down completely. At that point, you are paid to purchase electricity from the grid.
Choose an independent steering group
As an independent party ,Covolt manages your PV system entirely based on day-ahead market incentives. Unlike energy suppliers, we do not manage do not manage a portfolio.
That means:
- No conflict of interest
- No portfolio balancing
- Complete focus on cost reduction for your company
Flexible use of solar power systems is becoming the norm. Smart control systems reduce your energy costs on a long-term basis.
Want to know more? Contact us!
Sources:
BIS MEMORANDUM TO THE FLEMISH GOVERNMENT VR 2025 1909 DOC.0832/1BIS
BIS MEMORANDUM TO THE FLEMISH GOVERNMENT VR 2025 1909 DOC.0832/2TER
